It is commonly encountered in medicine, in particular veterinary medicine, that the dosage of a particular drug, medicament or nutritional agent is not required on a daily basis, but should be given at intervals which may range from very few days to several weeks. Current therapy provides for the human patient to note or remember when a particular dose is due, and for a non-human patient to be located, brought to a central area and given the drug, all of which can lead to missed or mistimed dosing which is to the detriment of the patient. In veterinary medicine a pulsed delivery system is available which provides for non-drug containing sections alternated with active sections, all driven at a constant rate, with the interval between doses being determined by the size of the layer without drug; a larger non-drug layer will cause larger intervals. However, this leads to very large devices, suitable only for the largest animals, or a limitation on the number of doses that can be provided from a single device. Alternatively, convoluted devices, such as spirals can be prepared which will avoid an extremely long device, but will provide for considerably expanded girth. The instant invention provides for a pulsatile device of compact size which avoids all of the problems of the prior art devices.